Grinding apparatus



June 8 1926.

E. C. LIPPS GRINDING APPARATUS Filed March 15 1924 3 mum H701 .lZvrqh dig-11,0 08

Patented June 8, 1926.

UNITED STATES PATENT OFFICE.

EVBAE C. LIPPS, OF DETROIT, MICHIGAN, ASSIGNOR 'I'O PACKARD MOTOR CAR COM- PANY, OF DETROIT, MICHIGAN, A CORPORATION OF MICHIGAN.

enmnmo APPARATUS.

Application filed March 15, 1924. Serial- No. 699,418.-

This invention relates to grinding apparatus and particularly to large high speed grinding wheels such as are used in the grinding of large surfaces. Such grinding wheels are frequently manufactured of abrasive material, such as carborundum, in the shape of large hollow cylinders having an outside diameter as large as thirty inches and an internal bore of twenty-six inches or more, the grinding being done on the annular face of the wheel. The hollow cylinders are usually supported in a driving hub to which they are clamped, or cemented, and are rotated through this hub in the ordinary way.

Because of the dimensions of the wheel and the low mechanical strength of the material, such wheels are subjected to a high percentage of breakage, both in manufacture and shipment, and in subsequent use. The breaking or cracking of such a wheel entails scrappin of the entire wheel, and as the cost of w eels of this type is quite high, the use thereof has frequently proved to be expensive.

One object of the invention is to provide a grinding wheel of the character designated in which breaks and cracks may be localized,

.andloss of the entire wheel upon the development of a minor injury may be prevented.

Other objects of the invention will apar from the following description taken 1n connection with the drawing, which forms a part of this specification, and in which: Fig. 1 is a plan view of a grinding wheel "constructed in accordance with the invention;

Fig. 2 is a side view, partially in section, of the grinding wheel shown in Fig. 1;

Fig. 3 is an enlarged fragmentary 'section, taken substantially on the line 3-3 of Fig 1, and

g. 4 is a similar enlarged section, taken.

substantially on the line 4-4 of Fig. 2.

Referring to the drawing, at 10 s shown a grinding wheel constructed in accordance with this invention, comprising segments 11, composed of carborundum or other suitable abrasive material, arranged to form a hollow cylinder. Between the upper portions of the segments 11 are suitable separators 12, which may be formed of thin strips of any suitable non-abrasive material, such as paper or cardboard. The separators 12 are preferably cemented as at 13 to the radially disposed faces of the segments 11, and any suitable cement may be employed for this purpose. It has been found, however, that a silicious cement is well adapted for this purpose, and that sodium silicate works particularly well. Y

The lower portion of the cylindrical wheel 10 is supported in asuitable driving hub 14, having a disk portion 16 on which the lower annular face of the cylinder .is adapted to rest, and having an axially disposed pe ripheral flange 17, adapted to embrace the lower portion of the segments composing the cylinder. This hub 14 is provided with a suitable drive shaft 18, -coaxial therewith and mounted in appropriate bearings (not shown), whereby the hub may be rotated in a manner well understood in the "art to which this invention relates.

The spaces between the segments 11 below the se ai'ators 13, and between the outer face 0 the segments 11 and the inner face of the flange 17 may be filled with any suitable material 19 having a cementing efitect thereon. An appropriate material for this purpose is sulphur, which is preferably poured into the designated spaces while in a molten condition and is allowed to harden therein.

. The upper portion of the cylinder 10 may formed on.the band, by means of which these bands may be contracted into close enga' ement with the segments 11.

%t will be evident that this structure provides a grinding wheel in which cracks and breaks may be localized in one or more of the se cute, so that upon the development of sue a' minor defect 1t is not necessary to throw away the entire wheel. In the event of a 'break or a crack occurring in one of the segments 11, the hoops 21 are loosened,

the separators 12 adjacent the damaged section are removed in any suitable manner, as bv sawing, the sulphur is softened as by heating, and the section taken out of the wheel. A new and undamaged section may be then inserted in place of the section removed, thus confining the loss to the cost of one of the sections.

It will be understood that various forms of the invention other than those described above may be used without departing from the spirit or scope of the invention.

lVhat is claimed is:

1. A cylindrical grinding wheel comprising segments of abrasive material, thin nonabrasive strips arranged between the segments, and a cement including silicate of soda to secure the strips between the segments. 1

2. -A cylindrical grinding wheel comprising segments of abrasive material, thin nonabrasive strips cemented between the segments for a portion of the length of the cylinder, the remainder of the space between the segments being filled with sulphur. 3. A cylindrical grinding wheel comprising segments of abrasive material, strips arranged between the segments, a silicious cement between the strips and the segments .for a portion of the length of the cylinder,

and a filler including sulphur in the remainder of the space between the segments.

4. A grinding wheel comprising segments of abrasive material arranged to form a hollow cylinder, a drive hub therefor having an axially disposed flange adapted to embrace the lower ends ofthe segments, thin separators between the upper ends of the segments, hoops clamping the segments above the hub, and filling material for the space between the segments and below the separators.

5. A grinding wheel comprising segments of abrasive material arranged to form a hollowcylinder, a drive hub adapted to embrace one end of the cylinder, paper separators cemented between the segments at the free end of the cylinder, and a sulphur filler between the segments below the separators and between the separators and said hub.

In testimony whereof I aflix my signature.

EVRAH c. LIPPS. 

